Sampling during the Initial Work Phases

Architects and engineers right across ATP work simultaneously together with our external partners in central building data models. Building Information Modeling (BIM) enables us to add information to each component so that every participant in the project has access to real-time information. We are now taking this “principle of BIM standardization” even further by working intensely on possibilities for the model-based evaluation of the use cases “model-based tender” and “model-based cost calculation.” Our aim is to make the use of BIM even more effective and comprehensive. For example, our offices have been using BIM2AVA, a workflow that we developed in-house and is independent of any norms, for several years. It addresses the iTWO-Revit interface between design and tender and ensures that Revit elements are (partly) automatically assigned the relevant iTWO equipment data (model-oriented quantity calculation). Thanks to DBD-BIM, a plug-in for programs such as Revit from Schiller und Partner GmbH, we now have a suitable equivalent for the German Region.

Why DBD-BIM?
Buildings in Germany are generally put out to tender using standard STLB-Bau performance description texts. And while it may be possible to generate projects using, for example, RIB iTWO – a construction project management software – there is still no dynamic link to model-based quantities. The content platform for building components DBD-BIM now ensures that the model can refer to STLB-Bau data.

How the tool works
We can already broadly sample the Revit model during very early work phases with the help of DBD-BIM information. The model information is firstly imported into the RIB system. Cost elements are then incorporated in the object book and a partly automatic cost calculation is produced. A specific evaluation of location-related cost parameters is possible at any time. We can adapt the sampling in every subsequent design phase before the tender is published in RIB iTWO. The construction cost evaluation in the model enables a quality check to be carried out at any time. Thanks to the direct connection of the IT systems Revit and iTWO and the complete incorporation of all DBD-BIM attributes from the modeling software into the RIB program, all necessary information is available at all times in both work programs – the author software and the project management system. We are also able to create cost elements and input them into RIB iTWO. The RIB software also offers access to all sample templates from DBD-BIM, building product manufacturers, the public administration, and ATP itself. In our everyday work, and dependent upon the project, we constantly work with a combination of model-oriented and manually input cost elements or specification items. This depends upon whether a cost calculation or tender is under consideration.

The advantages of the plug-in
We opted for DBD-BIM for many reasons: At ATP, STLB-Bau forms the basis for the tender process for German projects. To date, we have had to manually input STLB-Bau specification items into RIB iTWO and to add quantities by hand. DBD-BIM now offers us the opportunity to link one or several STLB-Bau deliverables to building components within the model. The plug-in also offers a seamless connection with the AVA software. The tool can be equated with a dynamic system. Basic decision-making criteria have a permanent impact on the rationale database. This means that building norms, classifications, and prices are automatically adapted every time there is a change in the configuration setting. If several deliverables are linked with one building component, this connection is dynamic. This means that certain features can sometimes be excluded due to the combination of deliverables. As a result, it is now possible to organize a model-based tender using STLB-Bau. The regionally differentiable prices that are input into the STLB-Bau database also mean that the plug-in can even be used for a model-based cost calculation during early work phases. These prices are updated twice a year.

The possibility of using the model to link defined features of building components during the planning process complements our design thinking. The implementation of DBD-BIM means that we are now facing a new work structure. BIM-compliant working requires us to shift specific working steps to earlier phases and to increase the awareness of designers and modelers of the functions of Work Phase 6.